Abstract
Quantitative mineral resource assessments used by the United States Geological Survey are based on deposit models. These assessments consist of three parts: (1) selecting appropriate deposit models and delineating on maps areas permissive for each type of deposit; (2) constructing a grade-tonnage model for each deposit model; and (3) estimating the number of undiscovered deposits of each type. In this article, I focus on the estimation of undiscovered deposits using two methods: the deposit density method and the target counting method.
In the deposit density method, estimates are made by analogy with well-explored areas that are geologically similar to the study area and that contain a known density of deposits per unit area. The deposit density method is useful for regions where there is little or no data. This method was used to estimate undiscovered low-sulfide gold-quartz vein deposits in Venezuela.
Estimates can also be made by counting targets such as mineral occurrences, geophysical or geochemical anomalies, or exploration “plays” and by assigning to each target a probability that it represents an undiscovered deposit that is a member of the grade-tonnage distribution. This method is useful in areas where detailed geological, geophysical, geochemical, and mineral occurrence data exist. Using this method, porphyry copper-gold deposits were estimated in Puerto Rico.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Bawiec, W.J., Griscom, Andrew, Krushensky, R.D., Marsh, S.P., McKelvey, G.E., and Scanlon, K.M., 1991, Mineral-resource assessment of Puerto Rico,in Good, E.E., Slack, J.F., and Kotra, R.K., eds., USGS research on mineral resources-1991 program and abstracts: U.S. Geological Survey Circular 1062, p. 4–5.
Bliss, J.D., 1986, Grade and tonnage model for low-sulfide Auquartz veins,in Cox, D.A., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 239–243.
Bliss, J.D., Menzie, W.D., Orris, G.J., and Page, N.J., 1987, Mineral deposit density— A useful tool for mineral-resource assessment,in Sachs, J.S., ed., USGS Research on mineral resources—1987 program and abstracts: U.S. Geological Survey Circular 995, p. 6.
Chung, C.F., Jefferson, C.W., and Singer, D.A., 1992. A quantitative link among mineral deposit modeling, geoscience mapping, and exploration-resource assessment: Economic Geology, v. 87, p.194–197.
Cox, D.P., 1985, Geology of the Tanamá and Helecho porphyry copper deposits and vicinity, Puerto Rico: U.S. Geological Survey Professional Paper 1327, 59p.
Cox, D.P., Acosta, Juan, Stewart, J.H., Arespon, Jesús, Brooks, W.E., Franco, Luis, Salazar, Edixon, Lopez, Yolanda, and Gray, Floyd, in press, Geologic map of the Guri and southern part of the Tucupita 2o by 3o quadrangles, Bolivar State, Venezuela: U.S. Geological Survey Miscellaneous Investigations Map, 1∶500,000 scale.
Cox, D.P., Orris, G.L., Gray, Floyd, and Page, N.J. in press, Density of gold vein deposits as a guide to informed-judgement estimates in the Venezuelan Guayan Shield: Kyoto, Japan, International Geologic Congress, 29th, Aug. 24–Sept. 3, 1992, Program with Abstracts, v. 1, p. 83.
Cox, D.P., and Singer, D.A., 1992, Distribution of gold in porphyry copper deposits,in DeYoung, J.H., Jr., and Hammarstrom, J.M., eds., Contributions to commodity geology research: U.S. Geological Survey Bulletin 1877, p. C1–C14.
Learned, R.E., and Boissen, Rafael, 1973, Gold—A useful pathfinder element in the search for porphyry copper deposits in Puerto Rico,in Jopnes, M.J., ed., Geochemical exploration, 1972: International Geochemical Exploration Symposium, 4th, London, U.K., 1972, Proceedings, p. 93–103.
Mattson, P.H., 1968, Geologic map of the Adjuntas quadrangle, Puerto Rico: U.S. Geological Survey Miscellaneous Investigations Map I-519, scale 1∶20,000.
Mosier, D.L., 1986, Grade and tonnage model for Homestake gold,in Cox, D.A., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 245–247.
Neter, John, and Wasserman, William, 1954. Fundamental statistics for business and economics: Boston, Allyn and Bacon, Inc., 738 p.
Root, D.H., Menzie, W.D., and Scott, W.A., 1992. Computer Monte Carlo simulation in quantitative resource assessment: Nonrenewable Resources, v. 1, p. 125–138.
Singer, D.A., 1993. Basic concepts used in three-part quantitative assessments of undiscovered mineral resources. Nonrenewable Resources, v. 2, p. 69–81.
Singer, D.A., and Cox, D.P., 1986, Grade and tonnage model for porphyry Cu−Au,in Cox, D.A., and Singer, D.A., eds., Mineral deposit models: U.S. Geological Survey Bulletin 1693, p. 110–114.
Wynn, J.C., Olmore, S.D., Gray, Floyd, Day, W.C., Sidder, G.B., and Page, N.J., 1991, U.S., Geological Survey mineral resource and tectonic studies in Venezuela,in Good, E.E., Slack, J.F., and Kotra, R.K., eds., USGS research on mineral resources—1991 program and abstracts: U.S. Geological Survey Circular 1062, p. 80–81.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cox, D.P. Estimation of undiscovered deposits in quantitative mineral resource assessments—examples from Venezuela and Puerto Rico. Nat Resour Res 2, 82–91 (1993). https://doi.org/10.1007/BF02272805
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02272805